1. Field of the Invention
The subject invention is generally related to resealable sealing assemblies and is specifically directed to an improved vessel inspection plug and assembly including an elastomeric plug and a receptive sleeve.
2. Discussion of the Prior Art
Many types of vessels and storage containers require periodic inspection for early detection of corrosion, deterioration of wall thickness and the like. In many typical installations, the vessels are insulated, making visual inspection of the outer surface difficult and impractical without disturbing the insulation. Typically, inspection holes are cut into the insulation to permit inspection. The holes then must be closed and resealed upon completion of inspection. Over the years, resealable sealing assemblies have been developed that permit permanent inspection holes to be cut into the insulation layer, with the assemblies being removable for inspection and resealable upon completion.
An example of a resealable sealing assembly is disclosed in U.S. Pat. No. 4,091,842, entitled: "Resealable Sealing Assembly for Inspection Port Hole", issued to E. L. Greenawalt, et al on May 10, 1978. As there disclosed, the sealing assembly includes a rigid sleeve which is permanently installed in the insulation port hole and a removable plug made of a compressible elastomeric material which, when inserted in the rigid sleeve, forms a weatherproof seal. This assembly has gained widespread acceptance throughout the industry and is applicable in a wide variety of textures of insulation from very soft and flimsy to hard. A weatherproof, adhesive-sealant is used to bond the sleeve to the insulation. An annular bulge is created in the sleeve to further mechanically bond the sleeve to the insulation.
While the resealable sealing assembly of the prior art has been widely accepted, it is not readily useful in applications where the insulation layer is of a ribbed or corrugated configuration. In addition, removal of the plug from the sleeve is somewhat cumbersome, particularly due to the excellent sealing characteristics of the assembly.
Other resealable assemblies are disclosed in U.S. Pat. No. 3,827,462, entitled: "Insulating Plug", issued to J. J. Celesta on Aug. 6, 1974; U.S. Pat. No. 3,658,096, entitled: "Insulating Plug", issued to R. E. Higuera on Apr. 25, 1972 and U.S. Pat. No. 3,233,775, entitled: "Flexible Plastic Plug", issued to J. S. Bozek on Feb. 8, 1966. None of the disclosed assemblies is readily adaptable for use with a ribbed or corrugated insulation jacket.
Therefore, there is a need for an improved sealing assembly that is readily adaptable to both smooth and ribbed insulation configurations and for an improved plug which is easy to remove and replace in the assembly.